Integrated Human-Computer Interfaces (HCI) provided as part of legacy systems manage a wide variety of equipment. The HCI units are tied to the internal hardware and software of the managed equipment and provided a dedicated mechanism for local control as well as immediate response to security or safety alerts.
A legacy or existing device designed to operate in a particular manner subsequently may be required to additionally support new equipment or modules that augment or enhance the original legacy device. For example, legacy communication equipment lacking some of the capabilities of future software defined radios or radios conforming to the U.S. Government's Software Communication Architecture, can be greatly enhanced by attaching a separate expansion unit which is compatible with the legacy equipment and which provides many of the more advanced capabilities and flexibility of a software defined radio. Preferably, such an expansion unit would connect to an existing or legacy communication device in such a manner that the unit provides additional capabilities to the existing device without the need for wholesale removal and exchange of the existing legacy device with a new device. To make retrofitting of legacy equipment cost effective, it is desirable to minimize modifications to the original equipment, including the human-computer interface. If the expansion unit does not include a full HCI capability, consideration must be made as to how to share the HCI of the legacy device with the expansion unit.
However, conventional integrated HCI devices are tightly coupled with the hardware and embedded software of the controlled legacy device and are not typically accessible via other external interfaces for use with expansion units or devices. Using the integrated HCI to provide access to expansion units would conventionally require software changes to the legacy unit which are expensive, hard to validate, and difficult to update on fielded systems. Moreover, the use of shared HCIs can result in critical message updates being missed when the HCI is not available to the legacy device (i.e., during use by an expansion unit).
Accordingly, there remains a need for a more effective approach to sharing an integrated human-computer interface of a legacy device with expansion units, which minimizes the hardware and software modifications required in the legacy device and avoids malfunction or disruption of operation of the legacy device.